/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package org.apache.skywalking.mqe.rt.operation.aggregatelabels;

public class AvgAggregateLabelsFunc implements AggregateLabelsFunc {

    private Double sum;
    private Integer count = 0;

    @Override
    public void combine(final Double value) {
        if (value == null) {
            return;
        }

        if (sum == null) {
            sum = value;
        } else {
            sum = sum + value;
        }

        count++;
    }

    @Override
    public Double getResult() {
        if (sum == null) {
            return null;
        }

        return sum / count;
    }
}
